Sound design the following only using the factory patch:
A bass sound:
This should be in Mono, contain sub frequencies and benefit from timbre (filter, waveform) modulation.
A pad sound:
A rich, thick and slowly evolving pad sound useful for sustained chords and pedal notes.
A bell like keyboard sound:
Try to emulate a bell like sound, FM synthesis can help with this, use AMP release to emulate the natural decay of a bell sound.
A percussive keyboard sound:
A short percussive keyboard sound that can cut through the mix.
A lead sound:
An expressive lead sound that offers useful modulation, this should be in mono. The Sync synthesiser engine is a good starting point for the oscillators.
Compose a short section of music with your sounds, (1 minute max) try to make sure they contrast each other. You can also use MIDI FX and other sequencing techniques that develop parts and instrumentation.
This is my experimentation so far, but I plan to re-work it & create something I like a lot more.